Magnet core and method of making the same



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GUSTAF W. ELMEN, OF LEONIA, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A. CORPORATION OF NEW,

Patented J an. 10, 1922.

YORK.

MAGNET GORE AND METHOD OF MAKING THE SAME.

1,403,305. Specification of Letters Patent. Ji'o Drawing. I

To all whom it may concern:

Be it known that I, GUSTAF W. ELMEN, a citizen of the United States, residing at Leonia, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Magnet Cores and Methods of Making the Same, of which the following is a full, clear, concise, and exact description.

This invention relates to magnet cores and particularly to telephone loading-coil cores of the so-called dust type, such as are described in the patent issued in myname, No. 1,297,126, dated March 11, 1919,

and the other patents therein referred to.

' The general object of the present'invem tion is to obtain a new and improved magnet core which is cheap to manufacture and possesses to a high degree, those. characteristics that are desirable in cores for loading coils and other electrical apparatus.

The present invention is broadly characterized by the treatment of finely divided magnetic material with a carbonizing agent for the purpose of hardening it. Hardened finely divided magnetic material so obtained is particularly suitable for the manufacture of cores for loading, coils and other telephone apparatus, by reason of the low hysteretic losses which will exist in such coreswhen subjected to the influences o1 telephonic currents.

The present method is applicable to any of the magnetic metals, iron, nickel and oohalt. It will, however, be described as applied to iron since this is themagnetic mate rial most usually employed for magnet cores.

The iron to be used may be either in the form of finely divided iron such, for exam- 40 ple, as what is commercially known as iron by-hydrogen or, inthe form of iron oxide.

In either case, the material is treated with a carbonizing agent such as carbon or an hydrocarbon, sufiicient heat being applied to facilitate the reducing and carbonizing process. Preferably, iron oxide is used, and with this is mixed enough finely divided carbon not only to reduce the oxide but also to J combine with the reduced metal. This mixture of finely divided iron oxide and carbon .is heated to a temperature below the melting temperature of the metal but high enough to cause the'reduction of the iron by the carbon and the combining of the excess carbon with Application and December 21, 1920. Serial No. 432,357.

the reduced metal. Such a temperature is about 300 to 400 (1. below the melting temperature of iron. This reducing and carbonizing treatment causes the material to take a spongy form from which it ma be reduced to a finely divided state by grin ing.

The hard iron particles so obtained may besorted by sifting, coated with insulating material, and formed into a solid in the usual manner as described in the patents hereinbefore mentioned.

What is claimed is:

1. The method ofmaking magnet cores which consists. in treating finely divided magnetic material with a carbonizing agent, coating the particles with insulating material, and forming a mass of such particles into a solid.

2. The method of making magnet cores which consists in treating iron in finely divided form with a carbonizing agent, coating the particles with insulating material, and forming a mass of such particles into a solid.

3. The method of making magnet cores which consists in heating to a carbonizing temperature a mixture of finely divided magnetic material and carbon, coating the particles with insulating material, and forming a mass of such particles into a solid.

4. The method of making magnet core-s which consists in heating to a carbonizing temperature finely divided iron and finely divided carbon, coating the particles with insulating material, and forming a mass of such articles into a solid.

5. he method of making magnet cores which consists in treating an oxide of a magnetic metal with a reducing and carbonizing agent, grinding up the resulting product, coating the particles thus obtained with insulating material, and forming a mass of such particles into a solid.

6. The method of making magnet-cores which consists in treating an iron oxide with a reducing and carbonizing agent, grinding up the resulting product, coating the particles thus obtained with insulating material, and forming a massof such particles into a solid.

7. The method of making magnet cores which consists in heating to a reducing and carbonizing temperature a mixture of iron oxide and carbon, grinding up the resulting vided iron hardened by heating to a corbonizing temperature with finely divided carbon, and insulating material separating the partirles of magnetic material.

In witness whereof, I hereunto subscribe my name this 20th day of December A. D, 1920.

GUSTAF W. ELMEN. 

